1. Field of the Invention
The present invention relates to a one-axis solar tracker system and apparatus which is simple to install, lower cost and the provision of an electric-magnetic locking device to resist from medium to strongest wind condition like hurricane or typhoon. In the global pursuit of using more green energy, solar farms is more and more popular to use one-axis tracker due to lower cost, higher wind resistance and easier for large scale solar farm installation, especially in lower latitude tropic zones. This disclosure proposes a low cost, low profile one-axis tracker with multiple posts support using a single or dual linear actuators driving mechanism for rotation. It is also equipped with a wind lock device to lock the solar tracker in horizontal neutral position during strong wind condition such as hurricane or typhoon. The stepwise wind lock device can further be applied to locking the solar tracker following each step of linear actuator activation enabling the disclosed solar tracker to operate in windy conditions.
2. Description of Prior Art
Reducing carbon dioxide and other pollutants production is the common cry by all the nations in order to curb the trend of global warming. In one area related to green energy revolution is the utilization of pollution free solar electric farm for future utility plants or any other large scale installation of solar panels. The solar panels installed on residential roof top becoming more and more popular scene in residential street. However, the fixed panel installation does not use the solar energy efficiently. There is a cosine angle multiplier of energy efficiency if the sun is slanted away from perpendicular exposure of solar panel. If the solar panel is flat in the horizon direction, the solar energy collected from sunrise to sunset accumulates only 64% of total exposed sun energy during day light. It is further multiplied by today's silicon solar cell efficiency of around 16%. The total daily efficiency results in only 10% of solar energy exposed on the solar panel. In other words, if we use fixed solar panel without sun tracking, it would lose about 36% of solar energy from sunrise to sunset. However, solar tracker on the market is not cheap today. If the solar tracker costs more than 36% of the solar panels it carried, one might as well go without solar tracker; since it does not worth the investment. Besides, moving parts on solar tracker naturally have the higher tendency of failure than fixed installation.
One-axis solar tracker installed on solar farm is not new. A typical solar-thermo parabolic trough reflector to collect solar heat uses one-axis tracker. However, the parabolic trough must be connected for a long length to heat up water to a high temperature steam for turbine engine generator. The one-axis solar tracker for solar panel is desired to be smaller in size for the following reasons: 1) The structure must be able to resist strong wind; the lower the structure, the better wind resistance it achieves, 2) The smaller tracker can be installed without big and heavy equipments, and it is easier to maintain and replace at human height level, 3) The installation of big structure is a major cost item. The design of solar tracker must be simple with minimum labor and machine cost involved in installation.
Another key issue of solar tracker is the problem of facing unusual strong wind like typhoon or hurricane. The solar-thermo parabolic trough can only be installed in limited locations on the earth where there is no hurricane or typhoon. Also, the parabolic trough needs excessive strong structure to hold up the reflector from wind force. On the contrary, solar photovoltaic system desires to be installed anywhere on earth with sunshine. Therefore, the structure must be able to hold up the strong wind during hurricane or typhoon seasons.